982 research outputs found

    Blind Source Separation with Optimal Transport Non-negative Matrix Factorization

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    Optimal transport as a loss for machine learning optimization problems has recently gained a lot of attention. Building upon recent advances in computational optimal transport, we develop an optimal transport non-negative matrix factorization (NMF) algorithm for supervised speech blind source separation (BSS). Optimal transport allows us to design and leverage a cost between short-time Fourier transform (STFT) spectrogram frequencies, which takes into account how humans perceive sound. We give empirical evidence that using our proposed optimal transport NMF leads to perceptually better results than Euclidean NMF, for both isolated voice reconstruction and BSS tasks. Finally, we demonstrate how to use optimal transport for cross domain sound processing tasks, where frequencies represented in the input spectrograms may be different from one spectrogram to another.Comment: 22 pages, 7 figures, 2 additional file

    Geometrical interpretation of the PCA subspace method for overdetermined blind source separation

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    In this paper, we discuss approaches for blind source separation where we can use more sensors than the number of sources for a better performance. The discussion focuses mainly on reducing the dimension of mixed signals before applying independent component analysis. We compare two previously proposed methods. The first is based on principal component analysis, where noise reduction is achieved. The second is based on geometric considerations and selects a subset of sensors according to the fact that a low frequency prefers a wide spacing and a high frequency prefers a narrow spacing. We found that the PCA-based method behaves similarly to the geometry-based method for low frequencies in the way that it emphasizes the outer sensors and yields superior results for high frequencies. Thes

    A Case of Mediastinal Cystic Lymphangioma

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    A 35-year-old Japanese manʼs routine chest radiography revealed an abnormal opacity. Chest computed tomography and magnetic resonance imaging showed a 5.5cm in dia. cystic tumor located at the left anterior mediastinum. The tumor was suspected to be an asymptomatic thymic cyst, and we chose observation for the tumor. At the 3-year follow up, the cystic tumor had gradually enlarged to 7.5cm in dia. and we thus performed a surgical resection via left video-assisted thoracic surgery. An immunohistochemical analysis showed that the cystic tumor was not a thymic cyst but rather a mediastinal cystic lymphangioma. Mediastinal cystic lymphangiomas are very rare, and they are difficult to diagnose preoperatively. Complete surgical resection is proposed for the treatment of such tumors

    Effect of molding processes on multiaxial fatigue strength in short fibre reinforced polymer

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    This study concerns the multiaxial static and fatigue strength properties. Short-glass-fibre-reinforced phenolic-resin composites (SGP) molded by injection and compression processes were subjected to tensiontorsion combined static and fatigue tests at room temperature under various test conditions. Tension – torsion combined static strength well agreed with Tsai-Hill failure criteria without depending on processes. Relationships between the maximum principal stress, ?p1, max, and the number of fracture cycles, Nf, were approximately linear in the whole range of up to 106 cycles. For a unified evaluation of multiaxial fatigue life for SGP, non-dimensional effective stress, ?*, defined by modifying Tsai-Hill failure criteria was applied. The slopes of ?*- Nf curves according to Baskin’s law were almost identical to the injection (n = 26.3) and compression (n = 26.2). We finally confirmed that the multiaxial fatigue life of SFRP could be predicted by using ?* with a unique Wöhler curve without relying on molding processes.&nbsp

    Volumetric Assessment of the Frontal Sinus in Female Adolescents and Its Relationship with Craniofacial Morphology and Orthodontic Treatment : A Pilot Study

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    The present study aimed to evaluate the correlation between frontal sinus morphology and craniofacial morphology, and to investigate the effects of orthodontic treatment on the development of the frontal sinus in female adolescents (mean age: 13.9 ± 1.3 years). In total, 53 patients were recruited and underwent cephalography and computed tomography before and after orthodontic treatment. Of these patients, most had a bilaterally symmetrical fan-shaped frontal sinus without any fusion. The average size and volume of the frontal sinus before orthodontic treatment were 45.8 ± 12.3 mm in breadth, 29.8 ± 7.3 mm in height, 22.7 ± 5.1 mm in depth, and 5151.6 ± 2711.4 mm2 in volume. Sinus volume in patients with skeletal Class III malocclusion tended to be larger than that in patients with skeletal Class I and II malocclusion. Upon comparison with the pretreatment measurements, the sizes and volumes of the frontal sinus were significantly larger following orthodontic treatment, regardless of the skeletal pattern; however, since these changes were small, the increases in the size and volume of the frontal sinus may have been caused by pubertal growth and not orthodontic treatment. The clinical relevance of the frontal sinus remains controversial

    A Rare Case of Inflammatory Myofibroblastic Tumor of the Diaphragmatic Parietal Pleura with Dissemination

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    Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm that occurs at different sites in the body. Pleural IMT in particular is especially rare. IMTs infrequently tend to have malignancy. We report a rare case of advanced diaphragmatic parietal pleural IMT with dissemination. A 30-year-old woman complained of right upper abdominal pain. Computed tomography showed a large lobulated mass over the right diaphragm, but no disseminated nodules were noted. Intraoperatively, we found the primary tumor arising from the diaphragmatic parietal pleura and a dozen disseminated nodules, and we removed them completely. The histopathological and immunohistochemical diagnosis was IMT
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